Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Interactions between histone deacetylase (HDAC) inhibitors and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), also known as Apo2 ligand, were examined in human leukemia cells (e.g., U937, Jurkat, and HL-60). Simultaneous exposure of cells to 100-ng/ml TRAIL with either 1-mM sodium butyrate or 2- micro M suberoylanilide hydroxamic acid resulted in a striking increase in leukemic cell mitochondrial damage, caspase activation, and apoptosis. Lethal effects were significantly diminished in U937 cells ectopically expressing dominant-negative caspase-8, dominant-negative Fas-associated death domain, CrmA (receptor pathway), or Bcl-2 or Bcl-X(L) (mitochondrial pathway). Analysis of mitochondrial events in U937 cells exposed to TRAIL/HDAC inhibitors revealed enhanced Bid activation and Bax translocation, loss of mitochondrial membrane potential, and cytoplasmic release of cytochrome c, Smac/DIABLO, and apoptosis-inducing factor. No changes were observed in expression of FLICE-like inhibitory protein, TRAIL receptors, or reactive oxygen species generation. TRAIL/HDAC inhibitor-induced apoptosis triggered caspase-dependent cleavage of p21(WAF1/CIP1); moreover, enforced expression of a nuclear localization signal deletant form of p21(WAF1/CIP1) significantly diminished lethality. Lastly, p27(KIP1), pRb, X-linked inhibitor of apoptosis, and Bcl-2 displayed extensive proteolysis. These findings indicate that coadministration of TRAIL with HDAC inhibitors synergistically induces apoptosis in human myeloid leukemia cells and provide further evidence that simultaneous activation of the extrinsic and intrinsic pathways in such cells leads to a dramatic increase in mitochondrial injury and activation of the caspase cascade.
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PMID:Simultaneous activation of the intrinsic and extrinsic pathways by histone deacetylase (HDAC) inhibitors and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) synergistically induces mitochondrial damage and apoptosis in human leukemia cells. 1470 68

We investigated the effects of FK228 on cell proliferation and apoptosis against human glioblastoma (GM) T98G, U251MG, and U87MG cells. Upon exposure to FK228, cell proliferation was inhibited, and apoptosis detected by the cleavage of CPP32 was induced. FK228 increased the expression levels of p21 (WAF-1) and of pro-apoptotic Bad protein in all GM cells. Furthermore, FK228 treatment also reduced the anti-apoptotic protein Bcl-xL in all GM cells and anti-apoptotic Bcl-2 in U87MG cells, thereby shifting the cellular equilibrium from life to death. An increased accumulation of histone H4 was detected in the p21 (WAF-1) promoter and the structural gene (exon 2) and the Bad structural gene (exon 2 and 3) upon treatment with FK228, as assessed by chromatin immunoprecipitation (ChIP) assay. Thus, the results indicated that an increased expression of p21 (WAF1) and Bad due to FK228 is regulated, at least in part, by the degree of acetylation of the gene-associated histone. We also found that FK228 inhibits cellular invasiveness and decreases MMP-2 activity. In addition, the growth of transplanted human GM m-3 cells into the subcutaneous tissue of hereditary athymic mice was significantly inhibited, and apoptosis was induced with FK228 treatment. The results suggested that FK228 might be useful in the treatment of human GM, although further studies will be needed.
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PMID:Histone deacetylase inhibitor, FK228, induces apoptosis and suppresses cell proliferation of human glioblastoma cells in vitro and in vivo. 1502 82

Present studies demonstrate that treatment with the histone deacetylases inhibitor LAQ824, a cinnamic acid hydroxamate, increased the acetylation of histones H3 and H4, as well as induced p21(WAF1) in the human T-cell acute leukemia Jurkat, B lymphoblast SKW 6.4, and acute myelogenous leukemia HL-60 cells. This was associated with increased accumulation of the cells in the G(1) phase of the cell cycle, as well as accompanied by the processing and activity of caspase-9 and -3, and apoptosis. Exposure to LAQ824 increased the mRNA and protein expressions of the death receptors DR5 and/or DR4, but reduced the mRNA and protein levels of cellular FLICE-inhibitory protein (c-FLIP). As compared with treatment with Apo-2L/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or LAQ824 alone, pretreatment with LAQ824 increased the assembly of Fas-associated death domain and caspase-8, but not of c-FLIP, into the Apo-2L/TRAIL-induced death-inducing signaling complex. This increased the processing of caspase-8 and Bcl-2 interacting domain (BID), augmented cytosolic accumulation of the prodeath molecules cytochrome-c, Smac and Omi, as well as led to increased activity of caspase-3 and apoptosis. Treatment with LAQ824 also down-regulated the levels of Bcl-2, Bcl-x(L), XIAP, and survivin. Partial inhibition of apoptosis due to LAQ824 or Apo-2L/TRAIL exerted by Bcl-2 overexpression was reversed by cotreatment with LAQ824 and Apo-2L/TRAIL. Significantly, cotreatment with LAQ824 increased Apo-2L/TRAIL-induced apoptosis of primary acute myelogenous leukemia blast samples isolated from 10 patients with acute myelogenous leukemia. Taken together, these findings indicate that LAQ824 may have promising activity in augmenting Apo-2L/TRAIL-induced death-inducing signaling complex and apoptosis of human acute leukemia cells.
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PMID:Cotreatment with histone deacetylase inhibitor LAQ824 enhances Apo-2L/tumor necrosis factor-related apoptosis inducing ligand-induced death inducing signaling complex activity and apoptosis of human acute leukemia cells. 1505 15

Magnesium ions have been shown to be a promising treatment for brain lesions caused by traumatic brain injury (TBI), as well as for the associated acute neurodegeneration and progressive functional deficits. This study investigated the effects of magnesium on the expression of the cell death/survival related proteins following TBI. Male Sprague-Dawley (SD) rats (n = 66, 280-320 g body weight) were subjected to sham surgery alone (n = 14), or to the surgery followed by a lateral fluid percussion brain injury of moderate severity (n = 52, 2.4-2.7 atm). The injured rats were randomly treated with an intravenous bolus of magnesium chloride (n = 26, 125 micromol) or saline vehicle (n = 26). The coronal brain sections were quantitatively analyzed for cell apoptosis and the expression of p53-related proteins, Bcl-2, cyclin D1 and PCNA at 1, 2, and 4 days post-injury by immunohistochemistry or in situ hybridization. Tissue damage was observed primarily in the ipsilateral cortex of the injured region with the induction of apoptosis and p53 mRNA level at 2 days after TBI. The expression of p53 and responding proteins (p21(WAF1/CIP1), Mdm2 and Bax) showed a temporal pattern similar to the apoptotic events in the time course experiments. They were induced in the early time points of days 1-2, decreasing by day 4 after TBI. In contrast, the expression of the cell survival related proteins - Bcl-2, cyclin D1, and PCNA - was most significant at day 4 post-injury, when the rate of apoptosis decreased. Magnesium treatment resulted in a reduction in apoptosis and expression of p53-related proteins. However, it had only a slight additive effect on the expression of the survival related proteins in the same time-course. These results provide a molecular basis for the efficiency of magnesium in treating TBI-induced tissue damage.
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PMID:A molecular basis for the efficacy of magnesium treatment following traumatic brain injury in rats. 1516 63

Apoptosis plays an important role in the regulation of bone turnover. Previously, we showed that 1,25(OH)2D3, the active form of vitamin D, may increase osteoblast survival by inhibiting apoptosis induced by serum deprivation. Human osteoblasts express the Fas receptor on their surface and its interaction with Fas ligand has been closely associated with human osteoblast apoptosis. To investigate the mechanism of 1,25(OH)2D3 inhibition of apoptosis in osteoblasts isolated from human calvaria, cells were exposed to Fas antibody. Visualization of apoptotic cells using annexin V revealed a significant decrease in apoptosis at 48 h in the presence of 1,25(OH)2D3 (14 +/- 4%, P < 0.04) compared with non-treated cells (52 +/- 4%). Furthermore, flow cytometric analysis of TUNEL-labeled osteoblasts showed a significant decrease in apoptotic cells in 1,25(OH)2D3-treated cultures (12 +/- 2%) at 48 h compared with non-treated cultures (44 +/- 3%, P < 0.04). Additionally, cells treated with 1,25(OH)2D3 survived longer as found by MTS analysis. To further explore the mechanism of 1,25(OH)2D3-mediated inhibition of apoptosis, we examined the changes in activation of death domain proteins, cleavage of caspases and mitochondrial regulators of apoptosis by Western blot analysis. A significant inhibition of caspase-8 cleavage and activity in 1,25(OH)2D3-treated cells was observed in conjunction with a decrease in the expression of the proapoptotic protein Bax with a significant increase in the expression of antiapoptotic protein Bcl-2. Furthermore, the levels of p21Cip1/WAF1, which inhibits the cleavage of caspase-8, was found to be highly induced in 1,25(OH)2D3-treated cells. In summary, these results demonstrate that the anti-apoptotic effect of 1,25(OH)2D3 in human osteoblasts after the activation of Fas-ligand is mediated by the regulation of components of both the mitochondrial and Fas-related pathways.
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PMID:Vitamin D inhibits Fas ligand-induced apoptosis in human osteoblasts by regulating components of both the mitochondrial and Fas-related pathways. 1520 41

Ursolic acid (UA) is a pentacyclic triterpene compound isolated from many types of medicinal plants and is present in human diet. It has been reported to possess a wide range of pharmacological properties, and is one of the most promising chemopreventive agents for cancer. Here, we report that UA inhibits the cell proliferation of human lung cancer cell line A549 and provide a molecular understanding of this effect. The results showed that UA blocked cell cycle progression in the G1 phase that was associated with a marked decrease in the protein expression of cyclin D1, D2, and E and their activating partner cdk2, 4, and 6 with concomitant induction of p21/WAF1. This accumulation of p21/WAF1 might be through a p53-dependent manner. Further, UA treatment also resulted in the triggering of apoptosis as determined by DNA fragmentation assay. This effect was found to correlate with the up-regulation of Fas/APO-1, Fas ligand, and Bax, and down-regulation of NF-kappaB, Bcl-2, and Bcl-XL. Taken together, our study indicated that UA might be a potential chemopreventive agent for lung cancer.
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PMID:Proliferative inhibition, cell-cycle dysregulation, and induction of apoptosis by ursolic acid in human non-small cell lung cancer A549 cells. 1535 Aug 28

Human parvovirus B19 has been found in various tissues in addition to erythroid lineage cells, and non-structural protein (NS1) is reported to induce cytotoxicity and apoptosis in erythroid lineage cells, but the mechanism in non-permissive cells is still unclear. To address this issue, we have constructed the NS1 gene in a cytomegalovirus episomal vector, pEGFP-C1 and transfected it into monkey epithelial cells, COS-7. EGFP-NS1 expression in transfected cells was monitored and assessed by fluorescence microscopy, RT-PCR and Western blot. The flow cytometric analysis showed that the NS1-transfected cells were arrested at G1 phase by paclitaxel treatment and there was increased apoptosis. The expression of p53, an important molecule in apoptosis and cell cycle regulation, and its downstream cell cycle kinase inhibitors p16(INK4) and p21(WAF1/CIP1) were up-regulated in the NS1-transfected cells. Also, increased expression of the pro-apoptotic Bcl-2 members Bax, Bad and activation of caspase 3 and caspase 9, but not the activation of caspase 8 or Fas were detected in the NS1-transfected cells. p53-induced Bax expression and subsequent activation of caspase 9 is probably the apoptotic pathway in NS1-transfected cells since activation of the caspase 9 was suppressed by the p53 inhibitor and apoptosis was significantly inhibited by the caspase 9 inhibitor. Our results suggest that the cell death of the NS1-transfected cells is associated with mitochondria related apoptosis. These findings might provide alternative information for further study and characterization of B19 NS1 protein in B19 non-permissive cells.
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PMID:Human parvovirus B19 non-structural protein (NS1) induces apoptosis through mitochondria cell death pathway in COS-7 cells. 1537 Jun 68

The functional significance of the cyclin-dependent kinase inhibitor (CDKI) p21(Cip1/WAF1) in paclitaxel-mediated lethality was examined in p53-null human leukemia cells (U937 and Jurkat). In these cells, paclitaxel exposure failed to induce p21(Cip1/Waf1) expression. Nevertheless, stable expression of U937 cells with a p21(Cip1/WAF1) antisense construct blocked paclitaxel-induced G(2)M arrest and increased mitochondrial injury, caspase activation, apoptosis, and loss of clonogenic potential. Consistent with these results, enforced expression of p21(Cip1/WAF1) in Jurkat cells increased the percentage of cells arrested in G2M and attenuated paclitaxel-mediated mitochondrial injury and apoptosis. Unexpectedly, enforced expression of p21(Cip1/WAF1) diminished paclitaxel-mediated inactivation of ERK, and reduced paclitaxel-induced activation of JNK as well as Bcl-2 phosphorylation. Together, these findings suggest that p21(Cip1/WAF1) partially protects p53-null human leukemia cells from paclitaxel-mediated lethality, and raise the possibility that p21(Cip1/WAF1)-associated perturbations in signal transduction pathways as well as Bcl-2 phosphorylation status may play a role in this phenomenon.
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PMID:The cyclin-dependent kinase inhibitor p21(CIP1/WAF1) blocks paclitaxel-induced G2M arrest and attenuates mitochondrial injury and apoptosis in p53-null human leukemia cells. 1546 49

The hepatitis C virus (HCV) core protein is believed to be one of viral proteins that are capable of preventing virus-infected cell death upon various stimuli. But, the effect of the HCV core protein on apoptosis that is induced by various stimuli is contradictory. We examined the possibility that the HCV core protein affects the ceramide-induced cell death in cells expressing the HCV core protein through the sphingomyelin pathway. Cell death that is induced by C(2)-ceramide and bacterial sphingomyelinase was analyzed in 293 cells that constitutively expressed the HCV core protein and compared with 293 cells that were stably transfected only with the expression vector. The HCV core protein inhibited the cell death that was induced by these reagents. The protective effects of the HCV core protein on ceramide-induced cell death were reflected by the reduced expression of p21(WAF1/Cip1/Sid1) and the sustained expression of the Bcl-2 protein in the HCV core-expressing cells with respect to the vector-transfected cells. These results suggest that the HCV core protein in 293 cells plays a role in the modulation of the apoptotic response that is induced by ceramide. Also, the ability of the HCV core protein to suppress apoptosis might have important implications in understanding the pathogenesis of the HCV infection.
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PMID:Suppression of ceramide-induced cell death by hepatitis C virus core protein. 1546 95

Resveratrol, trans-3,5,4'-trihydroxystilbene, was first isolated in 1940 as a constituent of the roots of white hellebore (Veratrum grandiflorum O. Loes), but has since been found in various plants, including grapes, berries and peanuts. Besides cardioprotective effects, resveratrol exhibits anticancer properties, as suggested by its ability to suppress proliferation of a wide variety of tumor cells, including lymphoid and myeloid cancers; multiple myeloma; cancers of the breast, prostate, stomach, colon, pancreas, and thyroid; melanoma; head and neck squamous cell carcinoma; ovarian carcinoma; and cervical carcinoma. The growth-inhibitory effects of resveratrol are mediated through cell-cycle arrest; upregulation of p21Cip1/WAF1, p53 and Bax; down-regulation of survivin, cyclin D1, cyclin E, Bcl-2, Bcl-xL and clAPs; and activation of caspases. Resveratrol has been shown to suppress the activation of several transcription factors, including NF-kappaB, AP-1 and Egr-1; to inhibit protein kinases including IkappaBalpha kinase, JNK, MAPK, Akt, PKC, PKD and casein kinase II; and to down-regulate products of genes such as COX-2, 5-LOX, VEGF, IL-1, IL-6, IL-8, AR and PSA. These activities account for the suppression of angiogenesis by this stilbene. Resveratrol also has been shown to potentiate the apoptotic effects of cytokines (e.g., TRAIL), chemotherapeutic agents and gamma-radiation. Phamacokinetic studies revealed that the target organs of resveratrol are liver and kidney, where it is concentrated after absorption and is mainly converted to a sulfated form and a glucuronide conjugate. In vivo, resveratrol blocks the multistep process of carcinogenesis at various stages: it blocks carcinogen activation by inhibiting aryl hydrocarbon-induced CYP1A1 expression and activity, and suppresses tumor initiation, promotion and progression. Besides chemopreventive effects, resveratrol appears to exhibit therapeutic effects against cancer. Limited data in humans have revealed that resveratrol is pharmacologically quite safe. Currently, structural analogues of resveratrol with improved bioavailability are being pursued as potential therapeutic agents for cancer.
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PMID:Role of resveratrol in prevention and therapy of cancer: preclinical and clinical studies. 1551 85


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